"Epic" is part of the loop
I'm new to the fandom, so I don't know if this is already an accepted theory. I think Hermes learned Epic from Orpheus.
Hermes: Where'd you get that melody?
Orpheus: I don't know. It came to me, as if I'd known it all along.
Hermes: You have. It's an old song, a song of love from long ago. Been a long time since I heard it, though.
Orpheus: You've heard that melody before?
Hermes: Sure.
Orpheus: Tell me more.
Hermes: Remember the tale I told you once, about the gods?
Orpheus: Which ones?
Hermes: Hades and Persephone. Remember how it used to be their love that made the world go 'round.
Orpheus: Yeah I remember now. But that was long ago.
Hermes: Tell it again, though.
Their exchange references the loop multiple times. Hermes heard the song a long time ago, when Orpheus sang it to Hades. Then Hermes sang it to Orpheus as a little boy. Epic I and Epic II are Orpheus's attempts at remembering exactly how the song went. What do you guys think?